Damascus, Syria ? Former President Carter defied U.S. and Israeli warnings and met Friday with the exiled leader of Hamas and his deputy, two men the U.S. government has labeled terrorists and Israel accuses of masterminding attacks that have killed hundreds of civilians.

Carter is the most prominent American to hold talks with Khaled Mashaal, whose Palestinian militant group claimed new legitimacy from the meeting along with two other sessions the Nobel laureate held with Hamas leaders in the Middle East this week.

“Political isolation (of Hamas) by the American administration has begun to crumble,” Mohammed Nazzal, a top figure in Hamas’ political bureau, told The Associated Press after Friday’s meeting at Mashaal’s Damascus office.

A senior Hamas official in Damascus, speaking on condition of anonymity because he was not authorized to represent the group publicly, described the meeting as “warm.”

But he said Carter did not receive a response to either of the two requests the former president made in the session: that Hamas halt its rocket attacks against Israel and that it agree to a meeting with Israeli Deputy Prime Minister Eli Yishai to discuss a prisoner exchange.

Nazzal said that Gaza-based Hamas leaders would travel to Syria on Saturday to confer with Mashaal and that Carter “will be informed of Hamas’ response in the coming days.”

Underscoring the impression that Carter did not win any concessions, Hamas said Friday that captured Israeli soldier Gilad Shalit will “not see the light” until Palestinian prisoners are also released in an exchange.

Carter’s convoy arrived at Mashaal’s office for the meeting under tight security, and reporters were prevented from getting near the site. The meeting was closed to media, and Carter was not available for comment.

But Carter, who brokered the 1978 Israeli-Egyptian peace and was awarded the Nobel Peace Prize in 2002, has defended what he calls his personal peace mission. He says Hamas, which controls the Gaza Strip, must be engaged in order to achieve peace between Israel and the Palestinians.

The controversy over his visit highlights two different approaches to foreign policy. Some, like Carter, believe is impossible to resolve a conflict without engaging all parties, even those responsible for attacks on civilians. Others, including the Bush administration, contend such meetings give credibility to hard-line militants and allow them to play for time when they are not serious about peace.

Echoing criticism from Secretary of State Condoleezza Rice before the trip, State Department spokesman Sean McCormack suggested Friday that Carter had opened himself up to “exploitation” by both Hamas and the Syrian government.

“We find it very odd that one would encourage to have a conversation between the Israeli government and Hamas, which doesn’t even recognize the right of the Israeli government to exist,” McCormack said. “Is that really the basis of a conversation?”

Several members of Congress also urged Carter not to meet Hamas leaders, saying it would confer legitimacy on the group behind dozens of suicide bombings and other attacks that have killed some 250 Israelis.

“We have a policy in this country about Hamas. And he is just deliberately undermining that policy, and it’s wrong,” Rep. Sue Myrick, R-N.C., told Fox News on Friday, calling for the State Department to revoke the former president’s passport.

Friday’s meeting, which followed a session between Carter and Syrian President Bashar Assad, was the first public contact between a prominent American figure and Hamas officials since the Rev. Jesse Jackson met with Mashaal in Syria in 2006.

The U.S. government has no contact with Hamas after designating it a terrorist organization in 1995 – an official label that means any financial or business transactions with the group are illegal. The government has also blacklisted Mashaal and his deputy, Moussa Abu Marzouk, making it illegal to conduct any transactions with them.

Hamas official Mushir Masri, in a fiery speech Friday to thousands of Hamas supporters in Gaza, said the meetings with Carter were proof that Hamas was not a terrorist group but a national liberation movement.